Heater



May 22 1934 J. LslA-lRoYER 1,959,935 v HEATER FiledOGt. 22. 1929 Inventor: Jacob Shroyer;

His Attorney latenteclMay 22, 1934 v i' UNITED STATES PATENT ,OFFICE nEATEa Jacob Il. Shroyer, Oak Park, Ill., assigner to Edison General Electric Appliance Company, a corporation of New York Application october 22, 1929, serial No. 401,558

1 claim. (ol. ss-s) My invention relates to heaters, more particu- The heating unit 11 is pivotally mounted upon larly to heaters of the type wherein edible matea supporting and operating arm 20 which also rials are subjected to a source of heat, and has is pivotally mounted so that the heating unit as a for its object the provision of an improved electric whole may be moved toward the support 10 to a 5 heater of this character. position in heating relation therewith, in which o Although it is not limited thereto, my'invention position it is shown in the drawing, and so that is particularly useful in connection with the it maybe moved away from the support to a preparation of edibles wherein the edible materemote position, which is indicated in the drawrialissubjected toabaking, browning or like heat ing by the dotted position of the arm 20. As

treatment. My invention is especially directed to shown, the arm 20 is pivotally mounted upon a portable electric heaters used in the production supporting frame 21 which is detachably secured of backed ice cream, meringue pies, au gratin to the base 13, by means of suitable screw fastenpotatoes and similar edible products. i ing means 22. The upper portion of thel cylinder I In carrying my invention into eiect in one is provided with a slot 14a which serves to re- 15 form thereof, I provide a suitable heating unit ceive the arm 20 so as to permit its motion to and 7.

which is supported so that it may be moved into from the support 10. heating relation with the edibles to be treated. I control the movement of the operating arm Moreover, I provide suitable means for autoand thus the movement of the heating unit away matically moving the heating unit away from the from the support 10 responsively to a predeteredible material upon the completion of the heatmined time interval and moreover, control the ing operation. Preferably, the heating unit is energization of the heating resistor responsively moved to a remote position with respect to the to the motion of the operating arm so that the edible material in response to a time interval. resistor will be energized when the unit is moved For a more complete understanding of my into its heating position with respect to the support vention reference should be had to the accom and willbe deenergized when the unit is moved 80 panying drawing in which the single ligure is an away from the support to its remote position. elevation in section of an electric heater embody- As shown, I provide a suitable dash-pot retarding my invention. ing and timing mechanism. This dash-pot, which Referring to the drawing, I have shown my preferably will be of the fluid type, comprises a invention in one form as applied to a portable `cylinder 23 pivotally mounted to the projecting 85 electric heater particularly useful in connection arms 24, provided on the supporting frame 21, a with the preparation of edibles. As shown, the piston 25 connected to the operating arm 20 by electric heater comprises a supporting member means of a piston rod 26, and an actuating spring 10 upon which the edible to be treated is placed, a 2'?. This spring is shown to be of the compression 5 suitable movably supported heating unit 11, contype and is positioned between the lower cylinder 9o l stituting the source of heat, and controlling head and the lower surface of` the piston 25 so means 12 provided to control the movement of that the force exerted by the spring tends to move the heating unit. A suitable base 13 is provided the piston upwardly, as viewed in the figure, to support these elements. As shown, a metallic and consequently tends to move the operating casing 14, preferably of cylindrical form, is arm in a clockwise direction. It will be under- 9 mounted upon the base 13. This casing sei-ves stood that the cylinder 23 is filled with oil or to support the edible support 10 and to house some similar suitable fluid both above and below the control mechanism 12. the piston, and that this fluid serves to retard The heating unit, which preferably is of the the'upward movement of the piston. As shown,

resistant type, comprises a helically coiled heatthe piston is provided with a suitable port or pasing4 resistor 15 mounted in` a suitable domesageway 30 leading from'the lower to the upper shaped heat deflecting support. The resistance face of the piston. This passageway is provided element is supported directly by a heat deflectwith a downwardly opening valve 31, which. is ing plate 16 which preferably is formed from a biased to its closed position by means of a comsuitable electrical and heat insulating material pression spring 32. It will be observed that by 105 such asporcelain. This plate in turn is supported reason of this construction the piston 25 will be by an outer metallic shell or guard 17. As shown, allOWed t0 move upwardly under the influence of the resistance element 15 is supported in a pluthe spring 27 since the fluid above the piston will rality 'of loops, which cover a relatively large y flow downwardly through the passageway 30 to area of the deiiectng surface of the plate 16. the lower portion of the cylinder. Moreover. it na will be observed that the piston will be moved upwardly at a rate determined by the strength of the spring 27 and the leakage past the valve 31.

To permit practically free movement of the piston downwardly within the cylinder so thatl 4that ,the arm 20 may be moved readily to its. lower position by reason of this valve construction in that as the piston is moved downwardly in its cylinder the valve 33a will be lifted from its seat, thereby permitting the oil to flow freely through the port 33 from the lower to the upper portion of the cylinder. Preferably although not necessarily so, the valve 33a will be of the ball type.

It is desirable to retard the initial motion of the heating unit away from the support 10 to a considerable extent and thereafter, permitI the arm to move rapidly to itsAremote position. Thus, it is desirable to hold the heating unit in its heating position until the heating operation has been substantially completed. To control the operating arm 20 so as to give the motion of the heating unit the above desired characteristics, 'I provide the valve 31 with a comparatively long valve stem or rod 31a. As shown, this rod projects considerably above the upper surface of the piston. It will be observed that when the piston has been moved upward a distance sufficient to cause the valve rod to engage the upper cylinder head, the valve will be opened and thereby permitthe. oil to flow freely from the upper to the lower portion of the cylinder. As a result of this operation the piston will be moved upward quickly under the influence of its actuating spring 27. Thus, .the piston during the initial portionY of its upward movement will be retarded while during the final portion of this movement it will be moved rapidly to its upper position.

-In order to control the energization of the heating resistor so that it will be energized when the heating unit is moved to its heating position and will be deenergized when the unit is moved to its remote position, Ivprovide a suitable control switch 34 which is operated responsively to the motion of the operating arm 20. As shown, this switchl 34 is interposed in the electrical connections" 35 leading from the twin supply conductor 36 to the heating resistor. 'I'his switch is provided with an operating arm 37 which when moved toits lower position, as shown in the drawing, closes the switch so as to effect an energization of the heating resistor and when moved to its upper position opens the switch so as to effect a deenergization of the heating resistor. As shown, this switch arm 37 is mechanically connected with the operating arm 20 by means of a rod 40 and a compression spring 41, this spring being interposed between the arm,37 and the lower end of the rod 40. It will be understood that this spring serves to protect the switch since its arm 37 has a definite limited motion. Preferably, the switch arm 37 will be connected with the arm 20 so that the switch will be closed before the lever 20 reaches its ultimate lower position and will be opened before the arm 20 reaches its ultimate upper position. This eliminates any error in timimr due to variation in switches. It is believed unnecessary for a proper understanding of this invention to describe in detail the construction and arrangement of this switch since any preferred well-known form may be used.

In the operation of the heater it will be understood that the edible to be treated will be placed upon the 'support 10 and that the arm 20 will be moved to its lower position shown in the drawing, so as to bring the heating unit to its heating position with respect to the edible. This downward movement of the arm 20 also serves both to close the switch 34 to effect an energization of the heating resistor 15 and to compress the actuating spring 27. When the arm 20 is released it will be moved` upwardly under the influence of the spring 27 to move the heating unit toward its remote position. The rate at which the heating unit is moved away from the support 10 depends upon the strength of the spring 27 and the rate at which the oil is permitted to flow from the upper portion of the cylinder through the piston port 30 to the lower portion of the cylinder. The arm will thus be retarded until the valve rod 31a has engaged the upper cylinder head after which the unit will be moved rapidly to its remote position. Another portion of the material to be treated may then be placed upon the support 10 and the previously described operation repeated, i. e., the arm 20 will be brought to its lower position to bring the heating unit in heating relation with the material after which the arm will be moved to its remote position by its actuating and timing mechanism.

Itis, of course, desirable at times to change the timing period. For this purpose, I have provided a suitable timing adjusting screw 42 which serves to limit the downward movement of the arm 20. Thus. the heating unit may be moved to various heating positions so that the retarded portion of its path of movement and consequently the time it remains in its heating position may be suitably varied. To accommodate the support 10 to'these adjustments it is itself adjustably mounted upon the cylindrical casing 14. As shown. the support 10 is provided with a supporting collar 43 which surrounds the cylindrical casing 14 and is secured thereto by means of a pressure saddle 44 forced inwardly against the outer surface oi' the casing by means of a-suitable set screw 45. Should the screw 42 be screwed upwardly, as viewed in the figure, so as to change the heating position of the heating unit, the support 10 likewise may be moved upwardly so that the material placed thereon will be subjected to the same heat intensity. Moreover, the supporting means provided for the support 10 permits it to be adjusted laterally with respect to the heating unit so that the articles may be conveniently placed thereon and removed therefrom.

An important feature of my invention is the provision for a ready removal of the heating unit and for a ready removal of the operating elements provided for the unit. Thus, it will be observed that the framework 21 serves to support the arm 20 and consequently the heating unit, the timing mechanism and the control switch as a unitary structure. This framework which is secured to the base 13 by means of the screw fastening means 22 is readily removable. It will be observed that by reason of this construction, to remove the entire mechanism is but necessary to unscrew the members 22, detach the leads 35 and withdraw the whole mechanism through the top of the casing. The casing is provided with a me 46 which normally closes the mouth vof the What I claim as new and desire to secure by Letters Patent of the United States is:

An electric heater comprising a hase, a casing mounted on said base, a support mounted on the exterior of said casing, a supporting frame Within said casing detach'ably secured to said base, an arm, means pivotally connecting said arm to said supporting frame, said arm extending outwardly from said casing so that it can be rotated on said pivotal connection, a heating element carried by said arm so that it is in heating relation with said support in one position of said arm and is remote therefrom in another position of said arm, a spring within said casing mounted on said frame and operably associated with said arm so that when said arm is moved to said one position said spring is compressed so as to tend to return said arm to said other position, and a dash pot within said casing mounted on said frame and operably associated with said arm so as to retard its motion to said other position, said dash pot operating to control said motion so that said arm is moved at a comparatively slow rate until it has been moved a predetermined distance toward said other position after which it is rapidly moved to said other position.

JACOB L. SHROYER.

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